The present invention relates to cargo handling apparatus, particularly apparatus for packaging elongate members. Aspects of the invention further relate to a retaining member for use in such an apparatus, for retaining elongate members in a packaged state.
Drilling boreholes by rotary drilling usually involves use of a drill string with a drill bit at the distal end, and a motor at the rig end. The drill string is conventionally made up of many drillpipe sections which are connected together by threaded box and pin connections. The drillpipe sections are typically 9.5-13.1 meters long, are relatively heavy, and require careful handling.
For storing and transporting drillpipe and other tubulars it is known to stack tubular lengths in cuboid bundles. The bundles are formed using perhaps four U-frames, with spacers being located between the arms of the U-frames and having upper and lower faces profiled to cooperate with tubular lengths of a particular diameter. The U-frames are spaced along the bundle and the bundle is lifted by slings or the like coupled to the U-frames. Accordingly, the spacers must be selected to suit the particular drillpipe dimensions, such that it is necessary for drillpipe suppliers and shippers to retain an extensive inventory of spacers.
An improved drillpipe packaging apparatus has been developed, and is described in International Patent Application PCT/GB00/00176. This improved apparatus comprises a pair of U-frames connected by spacers, on which are located deformable elastomeric packing members. In use, the elongate members to be packed are separated by the deformable members, which will deform to grip the elongate members securely. As the packaging members are deformable, the members may be used to package a variety of sizes of drillpipes, so obviating the need for suppliers and shippers to retain a range of packaging members. In order to bring about secure engagement of the drillpipes and packaging members, the apparatus further comprises a retaining arrangement to urge the stack of drillpipes and packaging members together. However, currently-known retaining arrangements are often unwieldy and may be difficult to fix correctly; further, existing retaining arrangements do not avoid the possibility that pressure may be applied unevenly to the stack of drillpipes, as a retaining arrangement on each side of each U-frame must be adjusted by hand separately.
It is among the objects of embodiments of the present invention to obviate or alleviate these and other disadvantages of the prior art.
According to a first aspect of the present invention, there is provided apparatus for packaging elongate members, the apparatus comprising: a frame comprising a base and side members; at least one packing member engageable with the frame, the packing member having a deformable portion for engaging elongate members to be handled; and means for retaining the packing member in contact with the elongate members, the retaining means comprising a pressure plate for urging the elongate members into contact with the packing member, engaging means for engaging a portion of the frame, and an adjustable tension member connected to the engaging means, the engaging means being mounted on a pivot on the pressure plate such that an increase in the tension applied by the tension member causes the engaging means to pivot and be urged against said portion of the frame.
Thus, the present invention enables a compression force to be applied to the packaged elongate members by adjustment of the tension member, which causes the pressure plate to be urged against the frame.
Preferably the pressure plate is provided with two ends, and an engaging means is located at each end of the pressure plate. This enables pressure to be applied over the length of the pressure plate, and hence more evenly across the elongate members. Each engaging means may be connected to a separate tension member; although preferably a common tension member is used. This ensures that equal tension may be exerted on each of the engaging means. In those embodiments in which separate tension members are provided, the tension members may nonetheless preferably be operatively associated such that adjustment of a single tension member causes adjustment of the remaining tension members to the same degree.
The tension member may for example comprise a chain, wire, cable, bar, rod, rope, and the like. The tension member may comprise a plurality of members. Each member may for example be connected to a separate engaging means. Preferably a pair of oppositely-oriented members are provided.
Preferably the tension member comprises a member movably received in a sleeve. Adjustment of the tension member may thus be effected by moving the member within the sleeve. Either the member or the sleeve may be connected to the engaging means, although preferably the member is so connected.
Preferably, the member and the sleeve comprise interacting male and female threads, such that relative rotation of the member and sleeve causes relative axial movement of the member and the sleeve. Conveniently the apparatus further comprises a handle for turning one of the sleeve and member, the handle incorporating a ratchet arrangement, such that the handle may only engage to turn the sleeve or the member in one direction. Thus, the handle may be used to increase the tension exerted by the tension member in order to apply pressure to the elongate members. Conveniently also a release mechanism is provided on the apparatus, to allow turning of the sleeve or the member in the other direction, to loosen the tension member. For example, a reversible ratchet arrangement may be provided.
Other embodiments of the invention may also incorporate alternative one-way ratchet mechanisms (for example, a winding may be arranged to turn only one way to allow tightening of a cable, or the like). Certain embodiments may also incorporate a quick-release mechanism, to rapidly release the tension in the tension members.
Preferably the engaging means comprises a hook. The hook may be single or paired, depending on the nature of the portion of the frame which is engaged. Other suitable engaging means include plates, levers, clamps, clasps, locks, chains, and the like.
The portion of the frame which is engaged may comprise recesses, protrusions, studs, bosses, or the like. In a preferred embodiment, the engaged portion comprises a pair of studs disposed on opposed sides of the frame; and the engaging means comprises a paired hook.
According to a second aspect of the present invention, there is provided apparatus for applying a compression force to a member held within a frame, the apparatus comprising a pressure plate, engaging means for in use engaging a portion of a frame, and an adjustable tension member connected to the engaging means, the engaging means being mounted on a pivot on the pressure plate such that an adjustment in the tension applied by the tension member causes the engaging means to pivot.
Preferably the pressure plate is provided with two ends, and an engaging means is located at each end of the pressure plate.
Preferably the tension member comprises a member movably received in a sleeve. Preferably two members are provided; preferably the members are oppositely-oriented in a sleeve. Preferably the member and the sleeve comprise interacting male and female threads. Preferably the apparatus further comprises a handle for turning one of the sleeve and the member. Preferably also the handle incorporates a ratchet arrangement, such that the handle may only engage to turn the sleeve or the member in one direction. Conveniently a release mechanism is also provided on the apparatus, to allow turning of the sleeve or the member in the other direction.
Preferably the engaging means comprises a hook; more preferably the hook is a paired hook.
According to a yet further aspect of the present invention, there is provided a method of applying a compression force to elongate members held within a frame, the method comprising the steps of:
providing a pressure plate, engaging means mounted on a pivot on the plate, and an adjustable tension member connected to the engaging means;
engaging the engaging means with a portion of a frame; and
adjusting the tension member to exert increased tension on the engaging means.
According to a further aspect of the present invention, there is provided an apparatus for applying a compression force to a member held within a frame, the apparatus comprising a pressure plate, at least two engaging means for, in use, engaging respective portions of a frame, and at least two adjustable tension members each connected to a respective engaging means for applying a holding force to the engaging means, the adjustable tension members being operatively associated such that the force exerted on each engaging means by each tension member is substantially equal, and the engaging means being mounted on respective pivots on the pressure plate such that a variation in the force applied by the tension member causes the engaging means to pivot and be urged against a portion of a frame.
According to a yet further aspect of the present invention, there is provided an apparatus for applying a compression force to a member held within a frame, the apparatus comprising a pressure plate, at least two engaging means for, in use, engaging respective portions of a frame, and an adjustable member connected to at least one of the engaging means for applying a force to the engaging means, the engaging means being mounted on respective pivots on the pressure plate such that an adjustment in the force applied by the member causes the engaging means to pivot, and the engaging means being operatively associated with one another and with the member such that the force exerted on each engaging means by the member is substantially equal.
According to a yet further aspect of the present invention there is provided an apparatus for applying a compression force to a member held in a frame, the apparatus comprising a pressure plate, at least two engaging means mounted on the pressure plate and for, in use, engaging respective portions of a frame, and an adjustable member for variably applying a substantially equal force to each engaging means, to urge the engaging means against the respective portion of the frame and so urge the pressure plate against a member held in the frame.
According to a still further aspect of the present invention, there is provided an apparatus for applying a force to a member held in a frame, the apparatus comprising at least two spaced portions for urging against a member, each portion comprising an engagement means for engaging a portion of a frame; the apparatus further comprising variable force means for variably applying a substantially equal force to each engagement means; wherein the engagement means are urged against the portion of the frame to a degree proportionate to the force applied by the force means, each engagement means serving to urge a respective spaced portion against a member.
The spaced portions may be separate, or may be portions of a unitary member; for example, a pressure plate.